Metal fasteners are commonly used in combination with file folders for securing papers within the folder. One of the more popular office-type prior-art sheet retainers used in binding a stack of hole-punched paper sheets together is the so-called ACCO™ prong binder shown in FIG. 1A hereof. In the ACCO™ binder a pair of prongs extending from a longitudinal base are inserted through spaced apertures from one side or top margin of a paper sheets stack, after which the prongs are bent 90° toward, or away from, each other against the top-most paper sheet in the stack. The paper stack is thus held temporarily at a margin by being pressed between the prong base and the pair of prongs extending therefrom. In some applications, prior to bending the prongs, a keeper, sometimes called a compressor bar, with rectangular or circular apertures is placed over the prongs from the opposite side of the stack so that the prongs pass through the apertures. The prongs are then bent 90° toward each other to rest in a longitudinal groove in the keeper and a pair of locking loops slidable along the groove are then positioned over the bent prongs to temporarily lock the prongs on the keeper. The paper stack is thus held temporarily at a margin by being pressed between the prong base and the keeper.
In either instance, the paper sheets in the stack are held securely together so that it is possible to leaf through the documents without them falling apart. But this type of fastener is subject to the criticism that when a paper, or a number of papers, resting within the stack has to be removed for any number of reasons, i.e., entering data, photocopying, presenting to a colleague, etc., all papers resting above any desired papers must also be removed from the stack. The need to remove papers from within a paper stack will happen quite frequently, e.g., with respect to medical records for hospital patients or legal documents for attorneys.
The problem associated with sequentially interconnected paper sheets on the prongs of the above mentioned prior-art fasteners is that, when there is a need to disconnect a paper, or a set of papers, from within the stack, it is necessary to individually disconnect (remove from the prong fastener) each paper in the stack resting above any desired papers. Disconnecting papers from the prong fastener results in an insecure stack of papers. Additionally, once the overlaying papers have been removed from the prongs, providing the user access to any desired papers lying beneath them, the user is left with the added task of realigning the hole-punched paper sheets of the now insecure (loose) group of overlaying papers that originally lay securely within the prongs of the fastener. This can be a tedious and time consuming task requiring the user to line up the punched holes of each individual paper with the prongs, sheet by sheet. Often, leading to much frustration, papers can become torn, misaligned on the prongs or not aligned at all, left laying freely within a folder or on a desk where they can easily be misplaced and/or lost.
The objective of this invention is to provide a fastening arrangement for detachably interconnecting hole-punched documents which has improvements and avoids the difficulties experienced by the prior-art fasteners described above.